Causal Reasoning About Human Behavior Genetics: Synthesis and Future Directions

Asymmetric genetic attributions for one's own prosocial versus antisocial behavior

People tend to rate prosocial or positive behavior as more strongly influenced by the actor's genes than antisocial or negative behavior. The current study tested whether people would show a similar asymmetry when rating the role of genes in their own behavior, and if so, what variables might mediate this difference. Participants were prompted to think about an example of their own behavior from the past year that was either prosocial or antisocial. Those in the prosocial condition rated the role of genetics in causing the behavior as significantly greater than did those in the antisocial condition. A mediation analysis suggested that this asymmetry could be accounted for by a tendency to view prosocial behavior as more natural and more aligned with one's true self than antisocial behavior. These findings add to a growing body of evidence suggesting that people's reasoning about genetics may be influenced by evaluative judgments.

Building causal knowledge in behavior genetics

Behavior genetics is a controversial science. For decades, scholars have sought to understand the role of heredity in human behavior and life-course outcomes. Recently, technological advances and the rapid expansion of genomic databases have facilitated the discovery of genes associated with human phenotypes such as educational attainment and substance use disorders. To maximize the potential of this flourishing science, and to minimize potential harms, careful analysis of what it would mean for genes to be causes of human behavior is needed. In this paper, we advance a framework for identifying instances of genetic causes, interpreting those causal relationships, and applying them to advance causal knowledge more generally in the social sciences. Central to thinking about genes as causes is counterfactual reasoning, the cornerstone of causal thinking in statistics, medicine, and philosophy. We argue that within-family genetic effects represent the product of a counterfactual comparison in the same way as average treatment effects (ATEs) from randomized controlled trials (RCTs). Both ATEs from RCTs and within-family genetic effects are shallow causes: They operate within intricate causal systems (non-unitary), produce heterogeneous effects across individuals (non-uniform), and are not mechanistically informative (non-explanatory). Despite these limitations, shallow causal knowledge can be used to improve understanding of the etiology of human behavior and to explore sources of heterogeneity and fade-out in treatment effects.

Ending genetic essentialism through genetics education

Genetic concepts are regularly used in arguments about racial inequality. This review summarizes research about the relationship between genetics education and a particular form of racial prejudice known as genetic essentialism. Genetic essentialism is a cognitive form of prejudice that is used to rationalize inequality. Studies suggest that belief in genetic essentialism among genetics students can be increased or decreased based on what students learn about human genetics and why they learn it. Research suggests that genetics education does little to prevent the development of genetic essentialism, and it may even exacerbate belief in it. However, some forms of genetics education can avert this problem. In particular, if instructors teach genetics to help students understand the flaws in genetic essentialist arguments, then it is possible to reduce belief in genetic essentialism among biology students. This review outlines our knowledge about how to accomplish this goal and the research that needs to be done to end genetic essentialism through genetics education.

The Meaning of "Cause" in Genetics

Causation has multiple distinct meanings in genetics. One reason for this is meaning slippage between two concepts of the gene: Mendelian and molecular. Another reason is that a variety of genetic methods address different kinds of causal relationships. Some genetic studies address causes of traits in individuals, which can only be assessed when single genes follow predictable inheritance patterns that reliably cause a trait. A second sense concerns the causes of trait differences within a population. Whereas some single genes can be said to cause population-level differences, most often these claims concern the effects of many genes. Polygenic traits can be understood using heritability estimates, which estimate the relative influences of genetic and environmental differences to trait differences within a population. Attempts to understand the molecular mechanisms underlying polygenic traits have been developed, although causal inference based on these results remains controversial. Genetic variation has also recently been leveraged as a randomizing factor to identify environmental causes of trait differences. This technique-Mendelian randomization-offers some solutions to traditional epidemiological challenges, although it is limited to the study of environments with known genetic influences.

Investigating perceived heritability of mental health disorders and attitudes toward genetic testing in the United States, United Kingdom, and Australia

Our beliefs about the heritability of psychiatric traits may influence how we respond to the use of genetic information in this area. In the present study, we aim to inform future education campaigns as well as genetic counseling interventions by exploring common fears and misunderstandings associated with learning about genetic predispositions for mental health disorders. We surveyed 3,646 genetic research participants from Australia, and 960 members of the public from the United Kingdom, and the United States, and evaluated attitudes toward psychiatric genetic testing. Participants were asked hypothetical questions about their interest in psychiatric genetic testing, perceived usefulness of psychiatric genetic testing, and beliefs about malleability of behavior, among others. We also asked them to estimate the heritability of alcohol dependence, schizophrenia, and major depression. We found a high interest in psychiatric genetic testing. In most cases, more than a third of the participants showed serious concerns related to learning about personal genetic predisposition, such as not wanting to have children if they knew they had a high genetic predisposition, or not wanting to choose a partner with a high genetic predisposition for a mental health problem. Finally, we found a significant association between most participants' attitudes and their lay estimates of heritability, which highlights the complexity of educating the public about genetics.

Genetic attributions and perceptions of naturalness are shaped by evaluative valence

Genetic influences on human behavior are increasingly well understood, but laypeople may endorse genetic attributions selectively; e.g., they appear to make stronger genetic attributions for prosocial than for antisocial behavior. We explored whether this could be accounted for by the relationship of genetic attributions to perceptions of naturalness. Participants read about positively or negatively valenced traits or behaviors and rated naturalness and genetic causation. Positively valenced phenotypes were rated significantly more natural and significantly more genetically influenced than negatively valenced phenotypes, and the former asymmetry significantly mediated the latter (Experiments 1 and 2). Participants' interpretation of what "natural" meant was not synonymous with valence or genetic attributions (Experiment 3). People ascribe differing degrees of genetic influence to the same phenotype depending on whether it is expressed in socially favored or disfavored ways, potentially representing a significant threat to public understanding of genetics.

Can an evolutionary perspective shed light on maternal abuse of children?

Although the theory of evolution lies at the heart of contemporary biology, its influence on the study of child psychology and psychiatry has been limited. In earlier work we have argued that evolutionary thinking has much of value for clinicians. Here, we explore the possible significance of evolutionary theory for understanding child abuse by mothers, particularly neglect, emotional abuse and physical abuse. We draw on the research of anthropologists, primatologists and evolutionary theorists to make predictions about the environmental circumstances under which one would expect such abuse to be more prevalent. We discuss how in modern, Western cultures there is less understanding of the circumstances that may influence, even predispose, a mother to limit her emotional and material commitment to an infant or child. We use four short vignettes of clinical cases and one longer case description to illustrate the insights offered to clinicians by an evolutionary approach. We see our work both as contributing to greater understanding of these matters and as facilitating more compassionate models of care and intervention for women in such circumstances.

Genetic essentialism: The mediating role of essentialist biases on the relationship between genetic knowledge and the interpretations of genetic information

PURPOSE

Genetic research, via the mainstream media, presents the public with novel, profound findings almost on a daily basis. However, it is not clear how much laypeople understand these presentations and how they integrate such new findings into their knowledge base. Genetic knowledge (GK), existing causal beliefs, and genetic essentialist tendencies (GET) have been implicated in such processes; the current study assesses the relationships between these elements and how brief presentations of media releases of scientific findings about genetics are consumed and affect the readers.

METHODS

An Australian national survey of GK, GET, and existing causal beliefs about health phenomena (heart disease and obesity) was conducted. Participants were also exposed to news headlines that offered genetic and non-genetic partial explanations of the same health phenomena and reported their evaluations of these headlines, as well as the effects of the headlines on their personal understanding of the health phenomena.

RESULTS

GK was negatively-associated with GET. Whereas GK did not directly predict the evaluation and effects of the genetic headlines, GET did. GK predicted the effects of the headlines indirectly via GET and via GET and existing causal beliefs.

CONCLUSION

GET seem to predict unwarranted effects of exposure to news headlines about genetic science, whereas GK seems to indirectly mitigate the same unwarranted effects.

Implicit associations of teleology and essentialism concepts with genetics concepts among secondary school students

In this article, we present the development and validation of an implicit association test for measuring secondary school students’ associations between genetics concepts and teleology concepts on the one hand, and between genetics concepts and essentialism concepts on the other hand. In total, 169 students from 16 school classes took part in the study, from January 2018 to May 2018. We investigated the strength of the aforementioned associations and the influence of various covariates such as gender, age, school class, or previous learning of biology on the association of teleology or essentialism concepts with genetics concepts through an analysis of covariance and a multi-level analysis. We found moderate associations between genetics and teleology concepts, as well as between genetics and essentialism concepts. These results might reflect a tendency of students of different ages and with various backgrounds to think about genes in terms of goals (teleology) and stability (essentialism), which should be investigated further in future research.

Using Anthropological Principles to Transform the Teaching of Human "Difference" and Genetic Variation in College Classrooms

Exposure to information about genetics is at an all-time high, while a full understanding of the biocultural complexity of human difference is low. This paper demonstrates the value of an "anthropological approach" to enhance genetics education in biology, anthropology, and other related disciplines, when teaching about human differences such as race/ethnicity, sex/gender, and disability. As part of this approach, we challenge educators across social and natural sciences to critically examine and dismantle the tacit cultural assumptions that shape our understanding of genetics and inform the way we perceive (and teach about) human differences. It calls on educators from both social and natural science disciplines to "de-silo" their classrooms and uses examples from our biological anthropology and sociocultural anthropology classrooms, to demonstrate how educators can better contextualize the "genetics" of human difference in their own teaching. Numerous opportunities to transform our teaching exist, and we are doing a disservice to our students by not taking these critical steps.

Students' Understanding of the Dynamic Nature of Genetics: Characterizing Undergraduates' Explanations for Interaction between Genetics and Environment

The idea of the interaction between genes and environment in the formation of traits is an important component of genetic literacy, because it explains the plastic nature of phenotypes. However, most studies in genetics education characterize challenges in understanding and reasoning about genetic phenomena that do not involve modulation by the environment. Therefore, we do not know enough to inform the development of effective instructional materials that address the influences of environmental factors on genes and traits, that is, phenotypic plasticity. The current study explores college students' understanding of phenotypic plasticity. We interviewed biological sciences undergraduates who are at different stages of their undergraduate studies and asked them to explain several phenomena that involved phenotypic plasticity. Analysis of the interviews revealed two types of mechanistic accounts: one type described the interaction as involving the environment directly acting on a passive organism; while the other described the interaction as mediated by a sensing-and-responding mechanism. While both accounts are plausible, the second account is critical for reasoning about phenotypic plasticity. We also found that contextual features of the phenomena may affect the type of account generated. Based on these findings, we recommend focusing instruction on the ways in which organisms sense and respond.

Public Understanding of Behavioral Genetics: Integrating Heuristic Thinking, Motivated Reasoning and Planned Social Change Theories for Better Communication Strategies

The field of behavioral genetics is experiencing a revolution following the development of genome-wide association studies and the availability of large datasets from international consortia. This rapid change could increase the existing gaps between basic research, translation, and public understanding of science. In the present work, we aim to synthesize key explanations of how public understanding of socio-scientific issues develop. We propose that integrating dual-process, motivated reasoning, and change management theories will increase the extent to which we understand, and can change, how people respond to findings from behavior genetics.